Structure formation of SiO$_2$-xerogels containing copper compounds of different phase composition

Technological methods of formation of pure and composite materials of composition SiO$_2$, SiO$_2$:Cu(NO$_3$)$_2\cdot$3H$_2$O, SiO$_2$:CuO and SiO$_2$:Cu$^\circ$, obtained on the basis of an aqueous dispersion of pyrogenic silica (aerosil) grade A-300, are considered. The method of scanning electron microscopy (SEM) was used to study the structural transformations occurring in the synthesized xerogel blanks during their heat treatment in air and in an environment of dried hydrogen (up to $T = 800^\circ$ С). By the method of uniaxial pressing on the basis of xerogels of the developed composition, tableted samples were formed in the form of disks with an initial diameter of about $13$ mm, for which the arising linear shrinkage and weight loss were established in the temperature range of $25$–$1200^\circ$ С.